Microsoft Reports Surge in Identity-Based Attacks Driven by Infostealers
Microsoft has reported a significant increase in identity-based cyberattacks, with a 32% rise in such incidents during the first half of 2025. The company’s annual threat assessment highlights a shift in attacker tactics, with hackers increasingly using stolen credentials obtained through infostealers or from large-scale data breaches to gain initial access to systems. Malware families such as Lumma Stealer, RedLine, Vidar, Atomic Stealer, and Raccoon Stealer, traditionally used after initial compromise, are now being deployed as first-stage payloads, making credential theft a foundational component of modern cybercrime campaigns.
This evolution in attack methodology has led to greater specialization within the cybercrime ecosystem, with distinct roles for initial access brokers, credential sellers, and ransomware operators who leverage stolen credentials for extortion. Microsoft also noted its collaboration with federal authorities to disrupt infostealer infrastructure, such as the Lumma Stealer network, though threat actors have demonstrated resilience by quickly reestablishing operations. The report underscores the growing threat posed by identity compromise and the need for organizations to strengthen credential management and detection capabilities.
Timeline
Oct 24, 2025
Flashpoint warns infostealer activity remains resilient despite takedowns
In October 2025 reporting, Flashpoint said infostealer operations continued to thrive despite disruptions by law enforcement and companies such as Microsoft. The report noted that operators quickly rebuilt infrastructure, sold logs cheaply on illicit markets, and adapted with stealthier delivery methods.
Oct 22, 2025
Microsoft publishes annual cyberthreat assessment on evolving attacker tactics
Microsoft's annual cyberthreat assessment, published in October 2025, described the growing use of infostealers as initial access tools and emphasized that multifactor authentication still blocks more than 99% of identity compromise attacks. The report also highlighted increased specialization among cybercriminals and rising abuse of social engineering to bypass defenses.
Jun 30, 2025
Flashpoint reports 1.8 billion credentials stolen from 5.8 million devices
Flashpoint said that in the first half of 2025, infostealer malware harvested more than 1.8 billion credentials from 5.8 million infected devices. The findings highlighted the scale of credential theft and the role of stolen usernames, passwords, and session tokens in follow-on intrusions.
Jun 30, 2025
Identity-based attacks rise sharply in the first half of 2025
Microsoft reported a 32% increase in identity-based attacks during the first half of 2025. The company said attackers increasingly used infostealers, secret-store theft, MFA bypass tactics, and ClickFix-style social engineering to gain initial access.
May 1, 2025
Lumma Stealer infrastructure seized by law enforcement
Law enforcement seized infrastructure tied to Lumma Stealer in May 2025 as part of efforts to disrupt a major infostealer operation. The disruption was temporary, with operators reportedly regrouping and restoring activity afterward.
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